feat: add catchup and unpaired reminder notifications

Add automatic push notifications for behind partners (escalating: 24h then
every 3 days) and daily unpaired user reminders. Includes edge functions,
migrations, notification preference toggles, and UI improvements to pairing
and swipe screens.

apps/supabase/functions/send-unpaired-reminder/index.ts

@@ -0,0 +1,164 @@
+import "jsr:@supabase/functions-js/edge-runtime.d.ts";
+import { createClient } from "https://esm.sh/@supabase/supabase-js@2.45.0?target=deno";
+
+/**
+ * Send push notification reminders to unpaired users.
+ * Called by pg_cron daily at 18:00 UTC.
+ *
+ * Targets users where:
+ * - couple_id IS NULL (no partner yet)
+ * - push_token IS NOT NULL (can receive notifications)
+ * - last_unpaired_reminder_at IS NULL or older than 3 days
+ * - unpaired_reminders_enabled is not false in notification_preferences
+ */
+
+const corsHeaders = {
+    "Access-Control-Allow-Origin": "*",
+    "Access-Control-Allow-Headers": "authorization, x-client-info, apikey, content-type",
+};
+
+const REMINDER_COOLDOWN_DAYS = 3;
+
+interface ExpoPushMessage {
+    to: string;
+    title: string;
+    body: string;
+    sound?: string;
+    data?: Record<string, unknown>;
+}
+
+async function sendExpoPushNotification(message: ExpoPushMessage) {
+    const response = await fetch("https://exp.host/--/api/v2/push/send", {
+        method: "POST",
+        headers: {
+            "Content-Type": "application/json",
+            Accept: "application/json",
+        },
+        body: JSON.stringify(message),
+    });
+
+    if (!response.ok) {
+        const error = await response.text();
+        console.error("Expo push error:", error);
+        throw new Error(`Failed to send push notification: ${error}`);
+    }
+
+    return response.json();
+}
+
+Deno.serve(async (req) => {
+    // Handle CORS preflight
+    if (req.method === "OPTIONS") {
+        return new Response("ok", { headers: corsHeaders });
+    }
+
+    if (req.method !== "POST") {
+        return new Response("Method not allowed", { status: 405, headers: corsHeaders });
+    }
+
+    try {
+        const supabase = createClient(
+            Deno.env.get("SUPABASE_URL")!,
+            Deno.env.get("SUPABASE_SERVICE_ROLE_KEY")!
+        );
+
+        const now = new Date();
+        const cutoff = new Date(now.getTime() - REMINDER_COOLDOWN_DAYS * 24 * 60 * 60 * 1000);
+
+        // Get unpaired users with push tokens who haven't been reminded recently
+        const { data: users, error: usersError } = await supabase
+            .from("profiles")
+            .select("id, push_token, couple_id, last_unpaired_reminder_at")
+            .is("couple_id", null)
+            .not("push_token", "is", null)
+            .or(`last_unpaired_reminder_at.is.null,last_unpaired_reminder_at.lt.${cutoff.toISOString()}`);
+
+        if (usersError) {
+            console.error("Error fetching unpaired users:", usersError);
+            return new Response(
+                JSON.stringify({ error: "Failed to fetch users" }),
+                { status: 500, headers: { ...corsHeaders, "Content-Type": "application/json" } }
+            );
+        }
+
+        if (!users || users.length === 0) {
+            return new Response(
+                JSON.stringify({ success: true, sent: 0, message: "No eligible users" }),
+                { headers: { ...corsHeaders, "Content-Type": "application/json" } }
+            );
+        }
+
+        // Get notification preferences for these users to check opt-out
+        const userIds = users.map((u) => u.id);
+        const { data: prefs } = await supabase
+            .from("notification_preferences")
+            .select("user_id, unpaired_reminders_enabled")
+            .in("user_id", userIds);
+
+        const disabledUsers = new Set(
+            (prefs || [])
+                .filter((p) => p.unpaired_reminders_enabled === false)
+                .map((p) => p.user_id)
+        );
+
+        // Check which users have a couple (invite code created but no partner yet)
+        const { data: couples } = await supabase
+            .from("couples")
+            .select("id, user1_id")
+            .in("user1_id", userIds);
+
+        const usersWithCouple = new Set(
+            (couples || []).map((c) => c.user1_id)
+        );
+
+        let sent = 0;
+        let skipped = 0;
+
+        for (const user of users) {
+            // Skip if user opted out
+            if (disabledUsers.has(user.id)) {
+                skipped++;
+                continue;
+            }
+
+            const hasCouple = usersWithCouple.has(user.id);
+            const title = "Sauci";
+            const body = hasCouple
+                ? "Your invite code is waiting! Share it with your partner to start discovering what you have in common."
+                : "Ready to get started? Create an invite code and share it with your partner!";
+
+            try {
+                await sendExpoPushNotification({
+                    to: user.push_token,
+                    title,
+                    body,
+                    sound: "default",
+                    data: { type: "unpaired_reminder" },
+                });
+
+                // Update last_unpaired_reminder_at
+                await supabase
+                    .from("profiles")
+                    .update({ last_unpaired_reminder_at: now.toISOString() })
+                    .eq("id", user.id);
+
+                sent++;
+            } catch (error) {
+                console.error(`Failed to send reminder to ${user.id}:`, error);
+            }
+        }
+
+        console.log(`Unpaired reminders: sent=${sent}, skipped=${skipped}, total=${users.length}`);
+
+        return new Response(
+            JSON.stringify({ success: true, sent, skipped, total: users.length }),
+            { headers: { ...corsHeaders, "Content-Type": "application/json" } }
+        );
+    } catch (error) {
+        console.error("Unpaired reminder error:", error);
+        return new Response(
+            JSON.stringify({ error: "Internal server error" }),
+            { status: 500, headers: { ...corsHeaders, "Content-Type": "application/json" } }
+        );
+    }
+});